[1] A. Bakker, J. Smit and R. Wegerif, Scaffolding and dialogic teaching in mathematics education: introduction and review, ZDM Mathematics Education, 47 (2015) 1047–1065. https://doi.org/10.1007/s11858-015-0738-8
[2] A. Gutierrez, A. Jaime and P. Gutierrez, Networked Analysis of a Teaching Unit for Primary School Symmetries in the Form of an E-Book, Mathematics, 9 no. 8 (2021) 30 pp. https://doi.org/10.3390/math9080832
[3] C. Hoyles and K. Jones, Proof in dynamic geometry contexts, In: C. Mammana and V. Villani (Eds), Perspectives on the Teaching of Geometry for the 21st Century, Dordrecht: Kluwer,(1998) 121–128.
[4] E. Barbeau, P. Taylor (Eds.), ICMI study-16 volume: Mathematical challenge in and beyond the classroom, New York, Springer, 2009.
[5] E. Swoboda and P. Vighi, Early geometrical thinking in the environment of patterns, mosaics and isometries, Springer: Cham, Switzerland, 2016.
[6] G. Polya, How to solve it, Princeton, NJ: Princeton University Press, 1957.
[7] J. Piggott, Rich tasks and contexts; NRICH, University of Cambridge: Cambridge, UK, (2011). Available online: https://nrich.maths.org/5662
[8] K. Komatsu and K. Jones, Interplay between paper-and-pencil activity and dynamic-geometry-environment use during generalisation and proving, Digital Experiences in Mathematics Education, 6 (2020) 123–143.
[9] L. B. Resnick and C. Zurawsky, Do the math: cognitive demand makes a difference, Res. Points, 4 no. 2 (2006) 1–4.
[10] M. Fahlgren and M. Brunström, A model for task design with focus on exploration, explanation, and generalization in a dynamic geometry environment, Technol. Knowl. Learn., 19 (2014) 287–315.
[11] M. S. Smith and M. K. Stein, Reflections on practice: selecting and creating mathematical tasks: from research to practice, Math. Teach. Middle Sch., 3 (1998) 344–350.
[12] M. Yerushalmy, Educational technology and curricular design: promoting mathematical creativity for all students, In R. Leikin, A. Berman, B. Koichu (Eds.), Creativity in mathematics and the education of gifted students, 2009 101–113.
[13] National Council of Teachers of Mathematics, Principles and standards for school mathematics, NCTM: Reston, VA, USA, 2000.
[14] N. Sinclair, M. Cirillo and M. de Villiers, The learning and teaching of geometry, In Compendium for Research in Mathematics Education, J. Cai, Ed., National Council of Teachers of Mathematics: Reston, VA, USA, 2017 457–489.
[15] R. Duval, The first crucial point in geometry learning: Visualization, How to see figures mathematically and not perceptually for becoming able to solve problems by oneself?, The Plenary Lecture presented at the 7th Mediterranean Conference on Mathematics Education - Section of the East-Meets-West on Innovation and Entrepreneurship - Congress and Exhibition, Nicosia, Cyprus, 2012.
[16] R. Huang and Y. Li, Teaching and Learning Mathematics through Variation, Part of the book series: Mathematics Teaching and Learning (MTAL), Sense Publishers. All rights reserved, 2017 43–67.
[17] R. Leikin, Challenging mathematics with multiple solution tasks and mathematical investigations in geometry, Part of the book series: Advances in Mathematics Education ((AME)), In Y. Li, E. Silver, S. Li (Eds.), Transforming mathematics instruction, Cham, Switzerland: Springer, 2014 59–80.
[18] R. Leikin, Stepped tasks: Top-down structure of varying mathematical challenge, Part of the book series: Research in Mathematics Education ((RME)), In Problem Solving in Mathematics Instruction and Teacher Professional Development, P. Felmer, P. Liljedahl, B. Koichu, Eds., Springer: Cham, Switzerland, 2019 167–184.
[19] S. Sharma, Use of theories and models in geometry education research: A critical review, Waikato Journal of Education, 24 no. 1 (2019) 43–54.https://doi.org/10.15663/wje.v24i1.644
[20] W. Eddie and L. Cheng, Learning through the Variation Theory: A Case Study, Int. J. Teach. Learn. High. Educ., 28 (2016) no. 2 283–292.
[21] A. Reyhani, Introduction of Piaget’s theory and Van Hiele-Van Hiele’s theory ,theory about geometry learning, Mathematical Education Roshd, 22 no. 2 (2014). [In Persian]
[22] A. Ghayor Najafabad, Unforgettable Proofs (Compendium of the book Unbelievable Results in Mathematics, collection of lectures by Omid Ali Shahni Karamzadeh), Shahid Chamran University Publications, Ahvaz, 2013. [In Persian]
[23] E. Momtahan, Unbelievable results in mathematics (a selection of articles and public talks by Omid Ali Shahni Karamzadeh, Shahid Chamran University of Ahvaz, 2019. [In Persian]
[24] Z. Goya, what is mathematics education not?, Two quarterly journals of theory and practice in the curriculum, 2 no. 3 (2013) 5–24. [In Persian]
[25] Z. Goya, A friend is at home and we are going around the world, Mathematical Education Roshd, 31 no. 3 (2013). [In Persian]
[26] Z. Goya and F. Haj Azizi, T P ACK standards of teacher training and development model, Mathematical Education Roshd, 36 no. 1 (2017). [In Persian]
[27] S. H. Alam Al-Hodaei, Principles of Mathematics Education, Nama Publications, 4th edition, 2017. [In Persian]
[28] S. Haqjo, A. Reyhani, Variation theory (V T ) and its applications in the design and implementation of inquiry learning in the mathematics classroom, 11th National Education Conference, Tarbiat Debir Shahid Rajaee University, 2018. [In Persian]
[29] S. Gholamazad, design and evaluation of rich tasks for learning, growth of mathematics education, 36 no. 2 (2017). [In Persian]
[30] S. M. Hamidi, The impact of software on learning mathematics (geometry), Master’s thesis, Shahid Chamran University of Ahvaz, 2012. [In Persian]
[31] M. Moradi Shalal, Linking Algebra and Geometry, Master’s Thesis, Shahid Chamran University of Ahvaz, 2012. [In Persian]
[32] N. Yafedian and A. Safabakhsh Chekosari, Teaching and Learning Geometry: Introduction to Van Hiele’s theory, University of Isfahan, Journal of Mathematics and Society, 4 no. 3 (2018) 9–22. [In Persian]